Negligence (negligentia in Latin) is a failure to exercise appropriate and or ethical rules of care expected to be exercised amongst specified circumstances. The area of tort law known as negligence involves harm caused by failing to act as a form of carelessness possibly with extenuating circumstances. The core concept of negligence is that people should exercise reasonable care in their actions, by taking account of the potential harm that they might foreseeably cause to other people or property.

Someone who suffers loss caused by another's negligence may be able to sue for damages to compensate for their harm. Such loss may include physical injury, harm to property, psychiatric illness, or economic loss. The law on negligence may be assessed in general terms according to a five-part model which includes the assessment of duty, breach, actual cause, proximate cause, and damages.

Elements of negligence claims

Some things must be established by anyone who wants to sue in negligence. These are what are called the "elements" of negligence.

Most jurisdictions say that there are four elements to a negligence action:

1. duty: the defendant has a duty to others, including the plaintiff, to exercise reasonable care,

2. breach: the defendant breaches that duty through an act or culpable omission,

3. damages: as a result of that act or omission, the plaintiff suffers an injury, and

4. causation: the injury to the plaintiff is a reasonably foreseeable consequence of the defendant's act or omission.

Some jurisdictions narrow the definition down to three elements: duty, breach and proximately caused harm. Some jurisdictions recognize five elements, duty, breach, actual cause, proximate cause, and damages. However, at their heart, the various definitions of what constitutes negligent conduct are very similar.